This invention relates to an electronic musical instrument capable of automatically conducting ensemble performance such as duet performance.
An electronic musical instrument in which an ensemble note or notes such as a duet note (duet tone) is automatically added to a melody note played in the keyboard is disclosed in the specification of U.S. patent application Ser. No. 220,099 filed on Dec. 24, 1980, and now abandoned and corresponding European Patent Application Preliminary Publication No. 0031598. In these prior applications, the key (scale tonality) of the musical piece to be played is previously designated by musical key (scale tonality) designation means and the tone pitch (or note interval) of a duet note to be added to a melody note is selected in accordance with the designated key and an accompaniment chord. Further, in this prior art electronic musical instrument, judgements are made with respect to modulation, passing notes, cadence and other factors by confirming the progression of the music (i.e., progression of melody and accompaniment chords) and a duet note is added to the melody note strictly following the musical theory. The method of adding a duet note according to this prior application, however, requires a player to previously designate the key (scale tonality) of the music to be played before starting the music, and further the addition of a duet note in a musically advanced manner in accordance with the progression of the melody may be liable to cause an unexpected change in the progression of the duet performance in the event that the player commits mistake in manipulating keys. Thus the musical instrument may be difficult for beginners.